Neco Model Questions Vol1 2017 Commerce Question 26

A warehouse stores three product categories A, B and C. The annual demand, unit cost, holding‑cost rate and volume per unit are: \(\text{Category A: }12{,}000\text{ units, }\text{unit cost }\₦500,\text{ holding‑cost rate }20\%,\text{ volume }0.02\,\text{m}^3\)\n\(\text{Category B: }8{,}000\text{ units, }\text{unit cost }\₦800,\text{ holding‑cost rate }25\%,\text{ volume }0.03\,\text{m}^3\)\n\(\text{Category C: }5{,}000\text{ units, }\text{unit cost }\₦1{,}200,\text{ holding‑cost rate }15\%,\text{ volume }0.05\,\text{m}^3\). The warehouse has a floor area of \(500\,\text{m}^2\) and a ceiling height of \(5\,\text{m}\). Two storage options are available: 1. Conventional shelving - floor area required equals total stored volume divided by the ceiling height. The annual floor‑space rent is \(\₦1{,}500\) per \(\text{m}^2\). 2. Vertical‑lift system - uses only \(30\%\) of the floor area required by conventional shelving but incurs an additional annual equipment cost of \(\₦200{,}000\). Which storage system should the warehouse adopt to minimise total annual cost? State the system name.